So I just had a Southbend Dual Disc Clutch installed in my NV5600 truck and the whole truck shakes. If you press the clutch pedal in the shaking stops. Once the truck warms up it shakes less. It feels like the truck is running on 5 cyl. What is going on? Did the shop install the clutch wrong? Is this normal?

I have now driven the truck a few thousand miles, towed a large percentage of those miles, some of those towing miles were on 6% mountain grades, and the transmission just gets better and better. 

 

In the begining it was on the stiff side to shift and it took quite a bit of time to shift.  Make no mistake, it wasn't difficult, and didn't feel bad, just stiff and slow.  Now, the transmission is MUCH less stiff and I would say is 30% faster to shift.  It's no race transmission, but I would say things are actually better than when stock.  I'm very happy with how everything feels and functions.

I'm on the other fence with Valair Dual Disc. The clutch itself is rock solid. Throw out bearing is loud in every one of these I've installed. Works good throws fairly easy. Gotta be slow with 3rd gear mostly. 4th and 5th just a bit slow to throw too.